In U.S. Pat. No. 7,430,810; Sergyeyenko et al. illustrated a laser, square, protractor kit which has a laser marker with a housing. The housing has a first positioning member. The protractor has a base with a second positioning member which cooperates with the first positioning member to position the housing on the protractor base. The protractor base also includes a third positioning member. A framing square is coupled with the third positioning member enabling the protractor to be positioned on the framing square.
In U.S. Pat. No. 6,839,974; Hitchcock described a multi-function layout square of modular construction having a laser that is capable of performing multiple functions. The multi-function square has a metallic outer casing with magnetic properties, with a protractor plate slidably, pivotally, and removably attached by thumbscrews to the casing that can be moved and rotated with respect to the casing and slid linearly along a portion of the length of the casing. When the protractor plate is removed the casing may be used as a level, a plumb bob, a ruler, and a compass. When the protractor plate is attached the tool may be used as a framing square, roofing framing square or rafter square, and a gauge or scribe for straight lines, arcs, or circles. The laser, a switch, and a pair of bubble level vials are contained in a module installed at one end of the casing, and a second module containing batteries is removably installed at the other end of the casing. Each module has electrical contacts that engage the interior surface of the casing and contacts that engage the batteries when the modules are installed and abutted. When the switch is on, a circuit is completed through the metallic casing, which electrically connects the batteries to the laser. The casing may be suspended vertically from a support surface by passing a string or wire through a bore in one of the thumbscrews, may be mounted on a tripod, or may be magnetically attached to metal objects.
In U.S. Pat. No. 6,763,595; Hersey described an apparatus for projecting an indication of alignment. The device forms a first output beam, and a second output beam that is substantially perpendicular to the first output beam. The first output beam indicates level, the second output beam indicates plumb, and the first and second output beams together indicate square. An error indicator indicates an error in the accuracy of the first and second output beams as indicators of level and plumb respectively. The error indicator can be deactivated, such that the first and second output beams together can be used at least to indicate square.
In U.S. Pat. No. 6,230,416; Trigilio showed a square holding a laser device for transmitting a laser beam to generate straight lines from the square to the surface upon which the laser beam impinges.
In U.S. Publication No. 2001/0049879; Moore, Jr. described a portable level and square laser alignment tool comprising a base and a separable L-shaped square. The base serves as an adjustable mounting surface upon which the L-shaped square is removably secured via a dual cam mechanism. The L-shaped square comprises two legs positioned at ninety degrees from each other thereby serving as a square to draw and/or test inside or outside right angles. Carried on each leg is a bubble level for providing a means to level the L-shaped square and/or the base. Additionally, a battery powered laser is attached to and is positioned in-line with each leg. The L-shaped square can be utilized alone or in conjunction with the base.
At least one feature that these and other laser squares known in the art have in common is that they are far too complex for the average hobbyist or home repair/remodeler. Thus, there remains a need for a simple, yet robust, square to assist the user is aligning a desired object at a right angle. The device should be dedicated to this one task, thereby be affordable to even those with limited means. The present invention is directed to solving this long felt need in the art.